The invention relates to novel prepolymers which are accessible from the formamides of oligomeric di- or polyamines (formamide-terminated oligomers) and di- or polyisocyanates.
Isocyanate-functional prepolymers of polyols and polyisocyanates have been known for a long time and are the basis of many existing commercial products.
For many uses, in particular in the fields of lacquers and adhesives, prepolymers having a low viscosity are desirable.
Prepolymers of diisocyanates and formamide-terminated oligomers are novel and are not known in the literature.
It has now been found that acylurea prepolymers which are distinguished by a low viscosity are accessible from formamide-terminated oligomers and polyisocyanates.